Eyewear lens having selective spectral response

Abstract

An eyewear lens provides for selective spectral performance in response to varying light conditions, including both changes in intensity and spectral distribution. The lens responds selectively to both ultraviolet and visible light, and exhibits different spectral transmittance characteristics under different lighting conditions, to provide for better vision for a wearer. In addition to this active response, the lens also may include a polarizer to further control light and to minimize the glare that interferes with clear vision.

1. A lens providing active response to light in the ultraviolet-visible spectral region, the lens comprising:
 a baseline lens portion characterized by a first specified visible light transmission spectrum;  
 at least one first photochromic activated by ultraviolet light in the range of 300-400 nm to produce a first colored, absorbing state in the visible light region;  
 at least one second photochromic activated by visible light in the range of 400-750 nm to produce a second colored, absorbing state in the visible light region; and  
 a polarizer.  
 
   
   
     2. A lens as defined in  claim 1 , wherein the polarizer is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     3. A lens as defined in  claim 1 , wherein the polarizer is characterized by transmission of light that is substantially constant across the visible light region. 
   
   
     4. A lens as defined in  claim 1 , wherein the first specified visible light transmission spectrum is characterized by transmission of light that is substantially constant across the visible light region. 
   
   
     5. A lens as defined in  claim 1 , wherein the first specified visible light transmission spectra is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     6. A lens as defined in  claim 5 , wherein the lens further comprises absorbers or reflectors of visible light. 
   
   
     7. A lens as defined in  claim 1 , wherein the at least one first photochromic comprises a material different from that of the at least one second photochromic. 
   
   
     8. A lens as defined in  claim 1 , wherein the first colored, absorbing state is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     9. A lens as defined in  claim 1 , wherein the second colored, absorbing state is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     10. A lens as defined in  claim 9 , wherein the first colored, absorbing state is different from the second colored, absorbing state. 
   
   
     11. A lens as defined in  claim 1 , wherein the lens further comprises absorbers or reflectors of ultraviolet light. 
   
   
     12. A lens as defined in  claim 11 , wherein the lens transmits less than 1% of total light having a wavelength below 380 nm. 
   
   
     13. A lens providing active response to sunlight, characterized by:
 a first, highest visible light transmission state during exposure to low light illumination;  
 a second, lowest visible light transmission state during exposure to bright sunlight illumination; and  
 a third, intermediate visible light transmission state during exposure to sunlight filtered through a UV-attenuating window medium.  
 
   
   
     14. A lens as defined in  claim 13 , wherein the UV-attenuating window medium is an automobile window. 
   
   
     15. A lens as defined in  claim 13 , wherein the third, intermediate visible light transmission state is characterized by absorption arising from at least one photochromic material activated by visible light. 
   
   
     16. A lens as defined in  claim 13 , wherein the second, lowest visible light transmission state is characterized by absorption arising from at least one photochromic material activated by ultraviolet light. 
   
   
     17. A lens as defined in  claim 13 , wherein the second, lowest visible light transmission state is characterized by absorption arising from at least one photochromic material activated by ultraviolet and visible light. 
   
   
     18. A lens as defined in  claim 17 , wherein the at least one photochromic material comprises at least one first photochromic material activated by visible light and at least one second photochromic material activated by ultraviolet light. 
   
   
     19. A lens as defined in  claim 13 , wherein the lens further comprises a polarizer. 
   
   
     20. A lens as defined in  claim 19 , wherein the polarizer is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     21. A lens as defined in  claim 19 , wherein the polarizer is characterized by transmission of light that is substantially constant transmission across the visible light region. 
   
   
     22. A lens as defined in  claim 13 , wherein the lens further comprises absorbers or reflectors of visible light. 
   
   
     23. A lens as defined in  claim 13 , wherein the first, highest light transmission state is characterized by a luminous transmission of between about 30% and about 85%. 
   
   
     24. A lens as defined in  claim 13 , wherein the first transmission state is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     25. A lens as defined in  claim 24 , wherein the wavelength-selective transmission differences are configured to provide improved visual acuity when the lens is used in low light conditions. 
   
   
     26. A lens as defined in  claim 24 , wherein the wavelength-selective transmission differences comprise absorption of visible light imparting a yellow or yellow-green color to the lens. 
   
   
     27. A lens as defined in  claim 26 , wherein the wavelength-selective transmission differences comprise reflection of light imparting a blue or bluish color to the lens. 
   
   
     28. A lens as defined by  claim 13 , wherein the second, lowest light transmission state is characterized by a luminous transmission of between about 6% and about 25%. 
   
   
     29. A lens as defined in  claim 13 , wherein the second, lowest light transmission state is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     30. A lens as defined in  claim 29 , wherein the wavelength-selective transmission differences are configured to provide improved visual acuity under bright sunlight conditions. 
   
   
     31. A lens as defined in  claim 29 , wherein the wavelength-selective transmission differences results in a reddish or red-blue color to the lens. 
   
   
     32. A lens as defined in  claim 29 , wherein the wavelength-selective transmission differences results in a grey color to the lens. 
   
   
     33. A lens as defined in  claim 13 , wherein the third, intermediate light transmission state is characterized by a luminous transmission of between about 10% and about 45%. 
   
   
     34. A lens as defined in  claim 13 , wherein the third, intermediate light transmission state is characterized by wavelength-selective transmission differences across the visible light region. 
   
   
     35. A lens as defined in  claim 34 , wherein the wavelength-selective transmission differences impart a brown or red-brown color to the lens. 
   
   
     36. A polarized lens providing active response to sunlight, the lens characterized by:
 a first, highest light transmission state during exposure of the lens to low light illumination;  
 a second, lowest light transmission state during exposure of the lens to bright sunlight illumination; and  
 a third, intermediate light transmission state during exposure of the lens to sunlight filtered through a UV-attenuating window medium.  
 
   
   
     37. A lens as defined in  claim 36 , wherein the third, intermediate light transmission state is characterized by absorption arising from at least one photochromic material activated by visible light. 
   
   
     38. A lens as defined in  claim 36 , wherein the second, lowest light transmission state is characterized by absorption arising from at least one photochromic material activated by ultraviolet light. 
   
   
     39. A lens as defined in  claim 36 , wherein the second, lowest light transmission state is characterized by absorption arising from photochromic materials activated by ultraviolet and visible light. 
   
   
     40. A lens as defined in  claim 39 , wherein the photochromic materials comprise one photochromic activated by both ultraviolet and visible light. 
   
   
     41. A lens as defined in  claim 36 , wherein the lens further comprises absorbers or reflectors of visible light.